Hi everyone
I would like to achieve having unidirectional relationships in my SwiftData project (which I believe is possible: https://developer.apple.com/documentation/updates/swiftdata?changes=_9) but I'm afraid I'm struggling to overcome the errors I'm experiencing.
For example, I have the following models:
@Model
final class Quota {
@Attribute(.unique) var id: UUID
var allowance: Int
@Relationship(inverse: nil) var fish: Fish
init(id: UUID = UUID(), fish: Fish, allowance: Int) {
self.id = id
self.fish = fish
self.allowance = allowance
}
}
@Model
final class Fish {
@Attribute(.unique) var id: Int
var name: String
init(id: Int, name: String) {
self.id = id,
self.name = name
}
}
However, when I attempt to save a quota as so:
let quota: Quota = .init(fish: Fish(id: 2, name: "Salmon"), allowance: 50)
modelContext?.insert(quota)
try save()
I keep getting the following error:
SwiftData.DefaultStore save failed with error: Error Domain=NSCocoaErrorDomain Code=1570 "%{PROPERTY}@ is a required value." UserInfo={NSValidationErrorObject=<NSManagedObject: 0x600002217390> (entity: Fish; id: 0x83319d001151328d <x-coredata://C76A2A64-146E-432F-A565-319B5A2F23F5/Fish/p12>; data: { id = nil; }), NSLocalizedDescription=%{PROPERTY}@ is a required value., NSValidationErrorKey=id, NSValidationErrorValue=null} %{PROPERTY}@ is a required value.
However, if I set up Quota and Fish with an inverse relationship then the data saves as expected, so I'm a little confused. Is there anyone out there who can provide some guidance as to why I'm seeing this error when I try to save a record in SwiftData with no inverse relationship?
I do fully understand about unidirectional vs bidirectional relationships but I have a scenario where I need the relationship to be unidirectional. Also, as a side note, the Fish record already exists in my database, but if I delete it and try to save the record I still see this error.
Thank you so much in advance for any help.